This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 1 |
| 3 | -1 |
| 4 | 1 |
| 5 | 1 |
| 6 | -3 |
| 7 | 5 |
| 8 | -7 |
| 9 | 9 |
| 10 | -7 |
| 11 | 1 |
| 12 | 9 |
| 13 | -23 |
| 14 | 41 |
| 15 | -55 |
| 16 | 57 |
| 17 | -39 |
| 18 | -7 |
| 19 | 89 |
| 20 | -199 |
| 21 | 313 |
| 22 | -391 |
| 23 | 377 |
| 24 | -199 |
| 25 | -199 |
| 26 | 825 |
| 27 | -1607 |
| 28 | 2361 |
| 29 | -2759 |
| 30 | 2361 |
| 31 | -711 |
| 32 | -2503 |
| 33 | 7225 |
| 34 | -12743 |
| 35 | 17465 |
| 36 | -18887 |
| 37 | 13881 |
| 38 | 569 |
| 39 | -26055 |
| 40 | 60985 |
| 41 | -98759 |
| 42 | 126521 |